1. Field of the Invention
The present invention relates to a plasma display panel (PDP) and, more particularly, to a sealing structure for forming a discharge space of the PDP.
2. Description of Related Art
A conventional PDP has a configuration in which, a pair of electrode rows, a dielectric layer for covering the electrode rows, and a protection layer for covering the dielectric layer (MgO layer), are formed in sequence on a display side glass substrate. On a rear glass substrate, on the other hand, formed in sequence are electrode columns orthogonal to the electrode rows, walls for defining discharge spaces formed between the electrode columns, and a fluorescent layer for covering the electrode columns and the side of the walls.
Subsequently, low melting-point glass paste having low melting-point glass flit and a binder mixed together is applied in the shape of a frame by means of a screen printing or the like to the peripheral portion on any one of the glass substrates. Then, the glass substrate is temporarily baked to form a sealing layer (a low melting-point glass layer).
Subsequently, both glass substrates are superimposed and heat treated at a temperature of 400xc2x0 C. with both substrates pressed against each other, thereby softening the sealing layer to be sealed. Then, the air between the glass substrates is exhausted and a discharge gas is sealed therebetween to complete a PDP.
Furthermore, since the sealing layer is composed of low melting-point glass paste, the layer generates a large quantity of thermally decomposed gases at the time of sealing during the heat treatment.
Accordingly, in the exhaust process after sealing, impure gases such as moisture and carbon dioxide remaining or trapped in the sealing layer are to be exhausted by heating the glass substrates to a temperature of 350-400xc2x0 C. near the softening point of the sealing layer. However, even in the panel which has been exhausted and has a discharge gas sealed, the impure gases remaining in the sealing layer are unavoidably released. This causes the surface of the protection film to be contaminated or the composition of the discharge gas to deteriorate, providing potential unstable discharge characteristics.
The present invention has been developed in view of the aforementioned problems. An object of the present invention is to provide a plasma display panel that is designed to provide stabilized discharge characteristics of the panel.
The plasma display panel according to a first aspect of the present invention is a plasma display panel comprising a sealing layer for sealing a peripheral portion of a pair of substrates opposed to each other across a discharge space and first walls for defining the discharge space of a display region, wherein on one of the substrates, in regions inside the sealing layer and outside the display region, second walls extended substantially in parallel to the sealing layer and having discontinuous portions and third walls opposed to the discontinuous portions of the second walls are formed.
The plasma display panel, according to a second aspect of the present invention, is the plasma display panel according to the first aspect of the present invention characterized in that the second and third walls have substantially the same height and width as those of the first walls, and are made of a low melting-point glass which is used for forming the first walls.
The plasma display panel, according to a third aspect of the present invention, is the plasma display panel according to the first aspect of the present invention characterized in that the first through third walls are formed by patterning a glass layer, comprised of low melting-point glass formed on one substrate, at the same time in accordance with respective patterns.
On one of the substrates, in regions inside the sealing layer and outside the display region, second walls extended substantially in parallel to the sealing layer and having discontinuous portions and third walls opposed to the discontinuous portions thereof are formed. This can prevent impure gases released from the sealing layer from being diffused into the display region and stabilize the processes for forming the second and third walls.
Furthermore, the manufacturing processes can be provided with improved efficiency and simplified by means of the simultaneous formation of the first through third walls.